That sounds more like the way I do it, but I use urethane auto paint and a detail spray gun. I've never heard of using the Windex/alcohol mixture. I use wax and grease remover and lacquer thinner in a pinch. Don't try lacquer thinner with rattle can paints. I also use 3M Scotchbrite pads. They don't load up like sandpaper and there's less tendancy to go through the primer to bare metal in places like lug edges.